Temperature-regulating device.



A. J. KERCHEB..

TEMPERATURE REGULATING DEVICE.

APPLICATION FILED NOV. 18, 1911. 1,047536 Patented Dec. 17,1912

2 SHEBTS'SHEET 1.

UNITED STATES PATENT OFFICE.

ARTHUR J. KERCHER, OF BERKELEY, CALIFORNIA, ASSIGNOR TO BERKELEY ELECTRIC COOKER COMPANY, OF BERKELEY, CALIFORNIA, A CORPORATION OF CALIFORNIA.

'TEMPERATURE-REGULATING DEVICE.

Specification of Letters Patent.

Patented D'ee.17,1912.

Application filed November 18, 1911. Serial No. 661,094.

To all whom it may concern:

Be it vknown that I, ARTHUR J. Kanonen, a citizen of the United States, and a resident of` Berkeley, county vof Alameda, and State of California, have invented certain new and useful Improvements in Temperature- Regulating Devices, of which the following is a specification.

The invention relates to temperature regulating devices for indicating when the desired temperature is obtained and particularly for heat regulating devices to be used in connection with electrically heated cookers to automatically break the electric circuit when the temperature reaches a certain maximum. y

The object of the invent-ion is to provide means for indicating .when the temperature ofa hot-plate to be used in a cooker reaches a certain maximum temperature.

Another object of the invention is'to pro- .,vide means for automatically opening 'the electric circuit in an electrically heated liotplate when the temperature vthereof reitches* al certain maximum. I

In tireless cookers a plate of iron orf'soapstone is used for impatting the nettessary *heat to the substance to be cooked. plate is generally heated on a gas drv coal range and placed in the 'cooker and the vesY selrlcotaining the substance to be cooked placldin the cooker adjacent to said hotplate. Various substances require various temperatures to properly cook them and a temperature 'above or below the required tcnipratiire v produces vpor and unsatisfactory results. Heretofore, as far as I am aware, no practical method has been employed to obtain these results, and conse- V quently cooking by means of hot-plates has not been as satisfactory as is desired. B

the use of my invention, however, the tem- .perature required is obtained and in electrically'hcatcd hot-plates, the electric circuit is'automatically opened to prevent a further rise in temperature. This device possesses other 'advantageous features, which, with the foregoing, will be set forth at length in .the following descripti0n,..-1lvhereY I shall outline in full thatforin or embodiment of the invention which I have selected for illustration in the drawings accompanying and yforming part of the present specification. The novelty of the inventin Will be included in the claims succeeding said dethat I do not restrict myself to the showing made by such drawings and descriptions as I may adopt. many variations Within'the scope of my invention as expressed in said claims. Y

Referring to the drawingsz-Figurel is a. vertical section through the lower portion of an electrically heated cooker, showing the hot-plate arranged therein 'and the device of my invention arranged in conjunction therewith. Fig. 2 is a vertical section through the circuit opening means of my invention. Fig. 3 is a front view of the same with the switch in closed position.

. Fig. 4 is an interior view of the device showing the switch contacts.

The device of my invention is particularly adapted to he used in connection with an electrically heated.hot-platelwiich is used l scription'f.. From this it will be apparent i in connection with an electrically heated,

cooker. The hot-plate 2 is generally arranged withina receptacle 3 formed of a heat insulating material 4 so that all of the 'heat is utilized in cooking the substance in ythe vessel 5 placed in the cooker. The lower part of the receptacle 3 adjacent the hotf )late is preferably lined with asbestos 6, for jobviousreasons. Arranged on the hotplate fis an electric heating unit 7, which, when a current is flowing therein imparts heat to the hot-plate. The automatically operating switch of my invention is arranged in t-he electric circuit and is adapted to be opened 1when the temperature ofthe hot-plate reaches a certain maxlmum. Arrangedon the hotplate and preferably integral therewith is a boss 8 having a cylindrical passage extending therethrough. It is evident that as the hot plate becomes heated, the integral boss is also heated ,to substantially the same temy perature. `Fitted into the passage in the]y boss is a metallic tube 9 the inner end of' which is partially closed by a flange 12 for reasons which will become apparent herein after. Within this tube is removably arranged a rod 13 having fixed at its center a piston or collar 1'4. This collar 14 is arranged within a cylinder 15 of larger 'diameter which istilled Wit-h a fusible metal or alloy 16. When placed in the tube 9, the cylinder bears against the flange 12, and the alloy being cold, the rod is held immovable with respect to the cylinder. When the alloy becomes heated to such an extent that it lattached to the switch block lt to which fuses the rod may be moved relative to the cylinder and this feature is employed in 0perating the switch to open the electric eircuit or indicate that the proper tennlierature is reached. The rod 13 extends from the cylinder in opposite directions, one end cxtt-rulimgY outwardly through the reci'iptaele 3 so that. the end hes in operative positionv lever 17 bearing against the bracket 23, the

lever being held raised at its outer cud by the rod 123. l'Vhen the allo)Y melts, however, the lever l' mores downward' toward the front face ol" the switch plate it. The lower part of the-braclwt L?, is cut away to form an aperture 25 through which the end ol the tev'er moved by. the spring 22, as soon as the rod has heen forced inward. 'lhe switch block 2l, is therefore rapidli the circuit, the eontaetsltn being moved out of connection willi the springsr contacts QSWQS). After moving outy ot contact with the brackety i3 the lever springs throughan arc'ot srbstantialtv 00" to the stop l on the. l

plate 24, holding` the switch open and thereby breaking the circuit.

vThe rod 1.3 is made'ot such length that when one end has been pushed inward after the alloy has melted, thc other end projects from the vli.nder the. proper distance so thatwhen the rod is reversed thecnd projects above the plate 24. In practice several rods with their accompanying cylinders are furnished with each control device. 'lhe cylinders,contain alloys which melt. at different temperatures, so that any temperature may be obtained by selecting the proper' rod.l

The lhot-piatzeis not "necessarily heated within the cooker as'tbe control device will operate with equal etlt .ii.uc y when thi` plate is removed trom the cooker. .'lhe flute need not necessarily he heated b y an electric curA rent. but .may be heated from other sources. l'Vhcu the plate becomes cated to the. proper temperature the switch is .thrown and acts'as a signal to indicate that the proper temperature has been reached.

Since thc cylinder l5 and thc fusible metal contents operate to release the switch, it may bc termed for the purposes ot brevity, a fusible metal cartridge.

l claim:

l, ln`an eleetricatl)r heated b-t heating element. au electric. ci

.moved to open ed thereto. a spring operated switch in Said with said hot-platc to open vthe switch when a certain temperature is reached.

The combination of a hot-plate, a cylinder. in close relation thereto, a fusible metal in said cylinder, a. rod passing through said cylinder and fusible metal, a'

sprintr pressed lever bearing against-` the end ot said rod adapted to indicate by its movement chen the fusible metal has melted.

3. ln au electrically heated hot-plate, a.

healing element, an electric circuit connect,

ed tht-reto, a manually operable switch in said circuit, a charge of fusible metal in close relation to aid hot-plate, and means connu-ting .said 'fusible metal with said switch adapted to allow the switch to open automatimill)r when the metal melts.

4. 'lhe combination with a hot-plate adap ed to be heated b v a currentI of electricity, of a n'mnuall)r operable. switch in the electric circuit. means tor holding the switch in the clos-.ed position and means operating iu conjunction with the hot-plate to release the switch when the temperature of' electrically heated hot-plrtcs comprising a fusible metal cartridge :nranged in closeA relation to the hot-plate and adapted to be heated thereby, anielcetric circuit, a switch in the clef-tric circuit. a rod extcni'ling from said cartridgeio said .switch and adapted to hold the switch in the closed position while the fusible metal is Solid, a spring pressed lever bearingr against 'the end of the rod and controlling. thc position ofv the? switch, said switcl` being arranged to be autonmtieally opened hy the inward movement. of the rod when the fusible metal has melted.

7. A. temperature regulating device for electrically heated hot-plates comprising a fusible nietal cartridge arranged in close. relation to thil hotfplate and adapted to be heated thereby, au electric circuit, a switch in the electricv circuit, a spring tendingto more :aid switch to thc open position, a. pivotall)r arranged spring' held lever on Said switch. a bracht-t adapted to be contacted with b y said lever to hold the switch in the -elosed perdita), a rod engaging said carsov tridge and said lever to hold it in engagei gitndinally when the fusible metal melts, an ment with said bracket, said rod being inovelectric circuit, a switch in the electric cirable to release the Switch when the fusible l cuit and means released by the movement of metal melts. l the rod, for opening saici switch.

8. An electrically heated hot-plate hav- In testimony whereof, I have hereunto ing a hollow,integral boss formed thereon, set my hand at San Francisco, Cal., this a metallic tube arranged in said boss having 13th day of November, 1911.

a partially closed inner end, a rod arranffed Y in said tube and projecting therefroni,D a ARTHUR J' KERCHER' fusible metal cartridge on said rod engag- In presence ofing said partially closed inner end, a spring l H. G. FROST,

pressed lever adapted to move said rod lon- .l R. HEFFERNAN. 

